The winter annual weeds you may have spotted growing in your lawn or garden beds during the fall season will once again begin growing, flowering and developing seed heads in early spring. There are many varieties of warm season weeds that first begin to sprout from the soil come springtime, but we are focused only on winter annual weeds and their most effective control period.
Common types of winter annual weeds
Most of the winter annuals are broadleaf weeds, with the one exception being Annual Bluegrass, a winter grassy weed. Below are some of the more common culprits homeowners could find growing in their lawns:
- Hairy Bittercress
- Carolina Geranium
Both types of winter weeds germinate and grow rapidly in the fall and part of winter, and by the time you venture out in the spring they could be growing once more, depending on the strategies you employed over the fall and winter seasons.
The best time to prevent and control winter annual weeds
Fall – roughly September through mid-October, and by using selective herbicides. The reason for this is that during periods of active growth after they germinate in fall, they most readily absorb the herbicide. Target this emergence and growth spurt by applying herbicide, which will then be absorbed up into and throughout the plant. This timeframe is most effective in eradicating these winter annual weeds, according to the Virginia Cooperative Extension.
Once you are past the initial growing season of fall and early winter for these weeds, your opportunity for use of selective herbicides has passed. At this point, nearing the end of their annual lifespan, they are fully matured and flowering and will soon die after going to seed. Consult your local lawn care professional for herbicide product recommendations and usage.
What to do if you didn’t apply fall herbicides last year
No need to fret. By spring, these winter annual weeds are near the end of their annual lifespan.
With temperatures on the rise and a robust, healthy lawn emerging as competition, these weeds will begin to die off. But not before they flower and spread seeds for fall germination! Proper post-emergent herbicide can help aid their decline, but the damage has already been done, or more accurately, sown for the next season. It’s up to you to break the cycle and treat these weeds during the upcoming fall season.
As with most types of weeds, the best weed control is a healthy lawn! Cultivating a healthy, lush lawn that limits opportunities for weeds to grow is one of the best solutions to prevent winter and other types of weeds.